A technique of symbolizing a driving scene of a host vehicle based on a traveling condition of the host vehicle and information on obstacles in the periphery of the host vehicle is conventionally known (Japanese Patent Application Publication No. 2013-242615). In Japanese Patent Application Publication No. 2013-242615, transition of the symbolized drive scene is predicted to determine driving operations.
When the technique of Japanese Patent Application Publication No. 2013-242615 is applied to autonomous driving, the symbolized drive scene greatly differs from the actual drive scene and highly-accurate autonomous driving may be thus difficult to perform.